Parkinson's disease is a chronic progressive disease which causes akinesia, muscular rigidity and tremor as a result of degeneration of dopaminergic neurons in the substantia nigra. It has been known that Parkinson's disease is caused by a decrease in the cerebral concentration of dopamine, a neurotransmitter, particularly in the caudate nucleus and putamen due to degenerative, vascular and inflammatory changes of the basal nucleus. Administration of levodopa is the most effective therapeutics and widely applied in order to supplement the decreased dopamine in the brain, particularly in the striatum. However, the single therapy with levodopa is problematic since it is associated with serious adverse reactions. Recently, trials to treat Parkinson's disease by inhibiting type-B monoamine oxidase, which is a dopamine decomposing enzyme, and preventing decomposition of dopamine are being conducted actively and deprenyl has been launched as a type-B monoamine oxidase inhibitor.
Now, in the Japanese Patent No. Sho 47-6302, it is mentioned that benzisoxazole derivatives, such as Compound A and B, are utilizable as local anaesthetics, antihistaminic agents, anti-inflammatory agents, tonics and antispasmodics with general effects on the nervous system as well as having cardiovascular effects. ##STR1##
Moreover, in Farmaco Ed. Sci., 23, 1081 (1968)., ibid., 24, 440 (1969)., it is mentioned that Compound B possesses anti-inflammatory effects and local (infiltration) anaesthetic effect. However, it is fully unknown that Compounds A and B have monoamine oxidase inhibitory activity.